Hi We are doing the floor insulation and some water plumbing ourselves - the house is strip to the joists and this is the last of the DYI phase before we get builders in to plaster, do the tiling, floor etc.

i think the thinnest possible floor insulation is this one https://www.kingspan.com/gb/en-gb/products/insulation/insulation-boards/optim-r/optim-r-flooring-system U values here https://www.homebuilding.co.uk/insulating-floors/

hi Suzzane, I think that your neighbour has a couple of options. lift the floor boards and place battens between the joists and place a layer of soundblock plasterboard between the joists. It needs to be fitted tight and filled before the floorboards are placed back on the joists. a layer of rock wool sound insulation below the layer will further increase the effect, but it depends on what is in the void. the other is to pay for you to drop your ceiling and have a independent resilient ceiling installed below the existing that can isolate the noise. again the use of a layer of insulation in the floor will help. They probably wont want to do this as the costs will be high, but you have rights over the added noise nuisance this will cause. There are propriety systems that can be used for both systems. I will try to post them for you to review. best Rowland

I would like to install underfloor insulation to my flat before fitting some nice new wooden floors. I'm trying to find a specialist installer but struggling, any ideas? I note it seems to be a thing that needs to be done properly otherwise can lead to problems. This is a good read, but doesn't recommend installers https://www.ecologicalbuildingsystems.com/post/best-practice-approach-insulating-suspended-timber-floors